1. Field of the Invention
The present invention is related to an orthopedic surgical implant for bone stabilization of peri-articular fractures, peri-articular osteotomies, and other orthopedic procedures involving periarticular regions.
Stable fixation in spongy or cancellous bone is, at times, a difficult problem in the field of orthopedic surgery, especially in orthopedic trauma and orthopedic osteotomy surgery. Often comminuted and geriatric/osteoporotic bone is difficult to stabilize with conventional screw and plate fixation. An equally difficult problem pertains to the placement of two large bone fragments in their proper sagittal and coronal orientation when performing orthopedic osteotomies.
2. Description of the Related Art
A procedure which is used commonly to treat early arthritis of the knee is the peri-articular valgus osteotomy. This osteotomy takes a "bow legged" deformity and creates a partial "knock kneed" deformity in order to transfer the weight off of the inner arthritic compartment of the knee onto the outer non-arthritic compartment of the knee. The average period of pain relief and maintenance of the knock kneed alignment is 5-7 years; at which time, the patient is left to live with his or her pain or depending on their age, may elect to have a total knee replacement. The fixation of these types of osteotomies has been commonly done with one piece plates, staples, and one piece blade plates.
These fixation systems are limited by their one piece solid designs and do not allow for small corrections which may be necessary because of anatomic variation. Even the correction of a few degrees of alignment may mean the difference between 5 years of pain relief and a lifetime of pain relief without the need for a second procedure.
The fixation of fractures, delayed unions, and non-unions in close proximity to the hip, knee, shoulder and ankle joints often poses similar and sometimes more troublesome problems as compared to peri-articular osteotomies. Fractures which occur in the elderly are often difficult to treat because of the osteoporotic nature of their bone.
Conventional plates rely on screw fixation into bone to secure the plate to the outside of the bone. The use of a blade plate attempts to overcome this lack of fixation. However, the proper placement of this blade plate is essential to return the normal anatomic alignment of the limb. It is often difficult to judge this placement because of the shattered bone fragments which accompany the fracture.
The conventional one piece blade plates, shown in FIG. 4, are constructed of a single piece of metal at fixed angles, but are without the ability to compensate for variations in bony anatomy. Therefore, even when precise placement of these plates is achieved when used for fracture fixation and periarticular osteotomies, the overall alignment of the limb may not be optimum because of the one piece fixed angled plate.
Although conventional two piece variable angle screw devices exist, they are currently used in hip fractures. These variable angle screw devices include a compression screw inserted into the femoral cortex, and include adjusting the angle of the device before screwing the plate into and flush with the femur, as shown in FIG. 5. However, this system does not allow for the treatment of metaphyseal fractures or osteotomies of the hip, knee, ankle, or shoulder by virtue of its inherent configuration.